Implement correct semantics of Boolean Conversion

runtime/vm/intermediate_language_ia32.cc

Index: runtime/vm/intermediate_language_ia32.cc
===================================================================
--- runtime/vm/intermediate_language_ia32.cc	(revision 42168)
+++ runtime/vm/intermediate_language_ia32.cc	(working copy)
@@ -23,6 +23,8 @@
 namespace dart {
 
 DECLARE_FLAG(bool, emit_edge_counters);
+DECLARE_FLAG(bool, enable_asserts);
+DECLARE_FLAG(bool, enable_type_checks);
 DECLARE_FLAG(int, optimization_counter_threshold);
 DECLARE_FLAG(bool, propagate_ic_data);
 DECLARE_FLAG(bool, use_osr);
@@ -32,7 +34,7 @@
 // on the stack and return the result in a fixed register EAX.
 LocationSummary* Instruction::MakeCallSummary(Isolate* isolate) {
   const intptr_t kNumInputs = 0;
-  const intptr_t kNumTemps= 0;
+  const intptr_t kNumTemps = 0;
   LocationSummary* result = new(isolate) LocationSummary(
       isolate, kNumInputs, kNumTemps, LocationSummary::kCall);
   result->set_out(0, Location::RegisterLocation(EAX));
@@ -43,7 +45,7 @@
 LocationSummary* PushArgumentInstr::MakeLocationSummary(Isolate* isolate,
                                                         bool opt) const {
   const intptr_t kNumInputs = 1;
-  const intptr_t kNumTemps= 0;
+  const intptr_t kNumTemps = 0;
   LocationSummary* locs = new(isolate) LocationSummary(
       isolate, kNumInputs, kNumTemps, LocationSummary::kNoCall);
   locs->set_in(0, Location::AnyOrConstant(value()));
@@ -248,11 +250,18 @@
   // Call the runtime if the object is not bool::true or bool::false.
   ASSERT(locs->always_calls());
   Label done;
-  __ CompareObject(reg, Bool::True());
-  __ j(EQUAL, &done, Assembler::kNearJump);
-  __ CompareObject(reg, Bool::False());
-  __ j(EQUAL, &done, Assembler::kNearJump);
 
+  if (FLAG_enable_type_checks) {
+    __ CompareObject(reg, Bool::True());
+    __ j(EQUAL, &done, Assembler::kNearJump);
+    __ CompareObject(reg, Bool::False());
+    __ j(EQUAL, &done, Assembler::kNearJump);
+  } else {
+    ASSERT(FLAG_enable_asserts);
+    __ CompareObject(reg, Object::null_instance());
+    __ j(NOT_EQUAL, &done, Assembler::kNearJump);
+  }
+
   __ pushl(reg);  // Push the source object.
   compiler->GenerateRuntimeCall(token_pos,
                                 deopt_id,